Process for the continuous heat treatment of lengths of textiles and the like



g- 1968 c. A. MEIER-WINDHORST 3,

PROCESS FOR THE CONTINUQUS HEAT TREATMENT OF LENGTHS 0F TEXTILES AND THE 'LIKE Filed July 24, 1964 2 Sheets-Sheet 1 INVENTOI? (m/vim wear/1am: dull 9M7 zduds YG- ATTORNEY 3, 1968 c. A. MEIER-WINDHORST 3,396,415

PROCESS FOR THE CONTINUOUS HEAT TREATMENT OF LENGTHS OF TEXTILES AND THE LIKE 2 Sheets-Sheet 2 Filed July 24, 1964 FIG. 2

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ATTORNEY United States Patent 9 Claims. (Cl. 8-1493) ABSTRACT OF THE DISCLOSURE An already treated length of textile material is further treated by condensation pre-heating in a steam-air mixture or pure steam to the saturation temperature of the steam and also heating it by condensation-free heating with a limited steam-developing heat effect.

This invention relates to a process for a continuous heat treatment of lengths of textiles or textile-like sheets.

Modern processes for refining textiles and the like are now preferably carried out in a continuous or semi-continuous manner. Such processes often include the impregnation of textiles by chemicals, such as bleaches, dyes and other refining substances. This impregnation is practically always followed by heat treatments in steam or, in certain cases, in a mixture of steam and air. The impregnation and the heat treatment are often continuous, so that one passes into the other. However, they are also often carried out separately since they are preferably carried out at different temperature ranges. The impregnation in that case is usually carried out at the lowest optimal temperature for that process and the heat treatment which often produces or furthers various chemical reactions, is carried out at the highest optimal temperature for this treatment. By way of example, heat treatments during dying with certain specific dyes have their higher optimal temperature ranges between 50 C. and 90 C.; in other cases, for example, when dying with vat dyes, as well as in steam treatments with cloth pressure and during bleaching, the temperature range is 100 C. In the course of dye treatment at 100 C., as well as when using vat dyes, it is also necessary to make certain that the heat treatment takes place in the absence of oxygen, i.e. in the absence of air. For dying operations and for other treatments wherein the absence of oxygen is not required-particularly such operations the optimal developing and fixing temperatures of which range between and C.the exposure treatments in the steam-air mixture during the so-called padroll process are carried out in such manner that the condensation temperature of the steam-air mixture being used is approximately equal to the ready goods temperature during the exposure treatment.

A temperature and exposure treatment taking place in the absence of oxygen results in bringing the partial steam pressure to the value 1, i.e. by providing pure steam instead of a steam-air mixture.

Prior art heating methods used for the abovedescribed heat treatments, partly with radiation heating and partly with condensation heatingin steam-air mixtures or in pure steamhave progressed already to combined radiation and steam condensation heatings. The manner in 5 which such heatings were combined was developed purely by chance or in special cases was produced empirically. The specific effects of such combination heatings and the natural laws to which they may be subjected were not known up to now; different prior art processes were found ice to have considerable variations in the reciprocal effects of the applied pro-heating methods.

An object of the present invention is to eliminate the drawbacks of prior art processes and to develop a particularly effective universal process for pre-heating operations during continuous heat treatments.

Other objects of the present invention will become apparent in the course of the following specification.

The present invention is based upon a very thorough investigation and clarification of the various effects taking place in different types of pre-heating and their variations, as well as of the possibilities of controlling them. A particularly advantageous application was found for the heat treatment taking place during treatments with dyes.

In accordance with the present invention, a length of material after continuous impregnation is guided in a manner known per se through a short sealing section or a narrow slit of the usual type into a special zone for carefully regulated pre-heating. In this zone the length is subjected to a pure condensation pro-heating in a steamair mixture while being freely guided, the predetermined length of the guided material amounting to from 1 m. to 3 m., depending upon the maximum operational speed and the condition of the material; or the material may be exposed to pure steam during treatments which preferably or necessarily take place at C. while air is excluded. Thereupon the length of material is guided to an adjacent zone where it is subjected to additional but condensationfree heating. This last-mentioned heating may consist of infra-red radiation heating, contact heating or high frequency heating. The output of the condensation-free heating is so set that at least a noticeable part of water condensed during condensation heating is again evaporated. The treated material is introduced into the fixing and repository chamber of usual construction only after the described carefully-regulated combined pre-heating and heat treatment have taken place. The pre-heating zone and the chamber are located one next to the other. Preferably, they are separated one from the other by a wall which may be provided with only a narrow slot for passage of the material.

In the course of the treatment the material is subjected to the following physical procedures:

The condensation heating, due to its particularly high heat transfer output with heat transfer amounts of 1-2000 kcaL/m. ch. in the case of dried material and 4-6000 kcal./m. C.h. in the case of completely wet material, will quickly raise the temperature of the material within the range of ready goods temperature. The steam-air mixture which passes through the pre-heating zone in a special way, can be so adjusted by suitable measuring and regulating devices that the saturation temperature corresponding to the partial steam pressure will be approximately equal to the required temperature of the repository treatment. Further heat transmission by a condensation-free heating will finally bring the temperature of the materialshould that be still necessary-to the required temperature. The larger part of this heat will effectively start the development of steam in the wet-impregnated material or in the material which acquired moisture by the condensation pre-heating. Thus the interior of the material, as well as its outer surfaces, will be freed from all adhering air and oxygen residues in a particularly effective manner. For heat treatment at temperatures below 100 C. it is important that the steam development should not substantially change the partial steam pressure of the steam-air mixture regulating the required temperature. This can be assured by suitably guiding the fiow, as will be described in detail hereinafter.

When the process of the present invention is carried out in the proper manner its treatments have the following advantages and characteristic features:

The present invention makes possible careful and quick regulation of the pre-heating which can be effectively adjustable with respect to temperature, while there need be only small additional heat consumption in the condensation-free heating.

The present invention provides an elfectively regulated steam development in the material.

The treated material acquires a safe and automatically regulated final temperature due to the partial steam pressure in the pre-heating chamber and a special guiding of the flow.

According to an advantageous embodiment of the present invention the pre-heating process is characterized by the step of-on the one hand-varying the time period during which the condensation-free pre-heating takes place. This step is of value for materials having less hygroscopic fibers, when the water saturation of the dye concentration by the condensation heating should be kept within certain limits. On the other hand, it is possible to adjust the percentage of the renewed evaporation depending upon the specific material and process requirements. In special cases it is of advantage to increase the evaporation output above the renewed evaporation of the condensation moisture.

Of particular importance is the correct guiding of the flow of the steam-air mixture or of pure steam which regulate the temperature of the material. Should the material have the same temperature in the chamber and in the pro-heating zone, then it is advantageous to conduct the steam out of the repository chamber in counter-current toward the material in such manner that there is a flow speed of about 0.5 m./sec. at the surface of the material being treated, particularly within the zones of the heat treatments and prior to the entry of the material into the repository chamber.

In prior art heat treating processes in which it was necessary to maintain certain predetermined steam or steamair conditions, the procedure was to blow pure steam into the treating chamber. The amount of this steam was usu ally regulated by a wet bulb thermometer of a manometer measuring partial steam pressure. The drawback of this prior art process consists in that with it is not possible to attain uniform distribution of steam and air in the treating chamber. When partial steam pressure is regulated, a certain amount of air must be introduced into the chamber through the slits through which the material is guided into the chamber and possibly through the slit through which it is removed from the chamber. The result is that there can be no specific steam-air mixture, particularly in the important section wherein the introduction of the length of material takes place. Thus it is not possible to provide a uniform temperature of the material and it is not possible to assure that the same type of treatment will always produce the same type of merchandise.

In accordance with the present invention, these prior art drawbacks are effectively eliminated by replacing pure steam with a predetermined steam-air mixture which is preferably produced by an injector and which is blown into the repository chamber or into the pre-heating zone. The ratio of the mixture in the injector can be regulated by the wet bulb thermometer set to a required temperature in the repository chamber; however, it is possible to adjust the mixture preliminarily and thus always introduce a constant steam-air mixture into the chamber. This steamair mixture is initially so set by hand that the wet bulb thermometer temperature in the treating chamber will be somewhat less than the one which is desired. The required temperature of the wet bulb thermometer is then automatically reached by supplying a small additional amount of steam.

It is advantageous to screen the guided length of material from the section wherein the steam-air mixture or the steam is being introduced into the chamber. For that pursame time as a guide for further guiding the steam or the steam-air mixture into the treating chamber.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing, by way of example, preferred embodiments of the inventive idea.

In the drawings:

FIGURE 1 shows diagrammatically and partly in section an apparatus suitable for a lengthy heat treatment.

FIGURE 2 shows diagrammatically and partly in section a treating chamber for a heat treatment of medium duration, and

FIGURE 3 shows diagrammatically and partly in section an installation for a short heat treatment.

In the drawings similar parts are indicated by similar numerals.

All heating devices shown in the drawings consist of a pre-heating zone and a repository chamber. The directions of movement of the lengths of material being treated and of the flow of steam-air mixture or of pure steam are indicated by arrows.

The pre-heating zone comprises a sluice separating outer air from the pre-heating zone, a section for pure condensation heating and a section for pure condensationfree heating.

FIGURE 1 shows a pre-heating chamber or zone 13 connected with a repository chamber for lengthy heat treatments, which is constructed as a pad-roll chamber 10. The zone 13 comprises a sluice 14 which separates outside air from the heating zone, a section 15 for condensation heating and a section 17 for heating which is free of condensation. The apparatus of FIGURE 1 also includes a zone 16 wherein the condensation heating and condensation-free heating may be superposed one upon the other. The zone 17 for condensation-tree heating may be heated by projectors 18 of infra-red rays.

According to the embodiment shown in FIGURE 1, a separating wall 19 is located between the pre-heating zone 13 and the chamber 10. The wall 19 is provided with a narrow slit constituting a passage for the length of material 20.

Preferably, the steam-air mixture or pure steam is introduced into the lower portion of the chamber 10 and is guided through the apparatus in counter-current to the direction of movement of the length of the material being treated. Steam is introduced through any suitable steam conduit 26 and its pressure can be adjusted to the desired amount by a manually operated pressure reducing device 25. This steam which is used for producing a steam-air mixture, is introduced into the treating chamber 10 through an injector 24. A certain amount of air is sucked in by the steam in the injector 24, and this amount of air can be regulated by a manually operable throttle valve 23. The actual volume ratio of steam to air is determined by the required treatment temperature and, consequently, by the set temperature of the wet bulb thermometer. The volume of the mixture which is being introduced, depends upon the dimensions of the chamber, the construction of the inlet sluice and the desired output.

It is also possible to introduce into the chamber a constant steam-air mixture which produces a somewhat lower temperature of the wet bulb thermometer. In that case, the required wet bulb thermometer temperature is automatically reached by the supply of an additional amount of pure steam through the valve 22. The regulating valve 22 is then operated by a measuring device 27 which is preferably located in the section into which the length of material is being introduced.

It is advantageous to provide a guiding metal sheet 21 which screens off the material from the direct contact with the steam-air mixture which is being introduced. The sheet 21 also produces a circulation of the steam-air mixture, so that the mixture is distributed completely uniformly throughout the chamber.

FIGURE 2 shows an apparatus having a pre-heating zone 13 which is connected with a chamber 12 having the shape of a J-box and suitable for heat treatment of medium duration. The zone 13 is provided with an entry sluice 14 a section 15 for condensation heating and a section 17 for condensation-free heating. The section 17 is heated by projectors 18 of infra-red rays. FIGURE 2 illustrates a single pipe 26 for introducing a steam-air mixture or pure steam, as well as a measuring device 27. A Water container 28 through which the length of material 20 leaves the apparatus, prevents atmospheric air from penetrating into the apparatus. In other respects the construction of this apparatus is substantially the same as that illustrated in FIG. 1.

FIGURE 3 shows an apparatus having a pre-heating zone 13 behind which is located a continuous passage loft 11 which is suitable for heat treatments of short duration and which contains upper and lower rollers guiding the material. The zone 13" is provided with an entry sluice 14", a section 15 for condensation heating and a section 17" for condensation-free heating. The section 17 is heated by projectors 18 of infra-red rays.

This construction also uses a water container 28 permitting the passage of the length of material 20 and providing a seal against atmospheric air. The apparatus has a pipe 26" for introducing steam and a measuring device 27. In other respects the apparatus is the same as those previously described.

It is apparent that the above-described examples have been given solely by way of illustration and not by way of limitation and that they are subject to many variations and modifications within the scope of the present invention. For example, the seal constituted by the water container may be also provided by a slit having a high flow resistance. The repository chambers may consist of suspension guides, a ring coil loft or the like. All such and other variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. A process for the continuous heating of treated lengths of material, comprising the steps of heating 2. treated length of material by condensation pre-heating in a gas at least a portion of which consists of steam to substantially the saturation temperature of the steam and also heating said length of material by condensation-free heating with limited steam-developing heat effect.

2. A process in accordance with claim 1, wherein said gas is a steam-air mixture.

3. A process in accordance with claim 1, wherein said gas is pure steam.

4. A process in accordance with claim 1, wherein said gas is a steam-air mixture, and wherein said saturation temperature is substantially that corresponding to the partial steam pressure of the steam-air moisture.

5. A process in accordance with claim 1, wherein said gas is pure steam, and wherein said saturation temperature is substantially that corresponding to the pure steam.

6. A process in accordance with claim 1, wherein the condensation pre-heating is immediately followed by the condensation-free heating.

7. A process in accordance with claim 1, wherein the condensation pre-heating is partially superposed upon the condensation-free heating.

8. A process in accordance with claim 1, wherein said length of material is moving in one direction and said gas is directed in counter-current to the movement of said length of material.

9. A process for the continuous heating of treated lengths of material, comprising the steps of heating a treated length of material by condensation pre-heating in a steam-air mixture to substantially the saturation temperature of the steam and also heating said length of material by condensation-free heating with limited steam-developing heat eflect, while introducing a constant steam-air mixture having a lower wet bulb thermometer temperature than the required one and then introducing a smaller additional amount of steam until the desired temperature is attained.

References Cited UNITED STATES PATENTS 1,992,753 2/ 1935 Karlson et a1 68--5 X 2,346,186 4/1944 Poesl 8l49.3 X 2,456,301 12/1948 Miller et a1 34-18 2,655,802 10/1953 Rarich 68-5 2,833,136 5/1958 Prince et al 68-5 2,877,636 3/1959 Dungler 68-5 3,196,642 7/1965 Terhune et al 68-5 3,235,973 2/1966 Smith 34155 WILLIAM I. PRICE, Primary Examiner. 

